A) Time-Domain/Transient Analysis main advantage is its ability to handle very strong non-linearities in large circuits. Its robustness results in part from the fact that small time steps can be used in the time-domain integration. As long as the non-linearities are continuous, the time steps can always be made short enough so that the circuit voltages and currents change very little between steps.
B) Harmonic Balance Analysis used to complement conventional Transient Analysis Methods especially in:
- Matching circuits contain elements such as dispersive transmission lines, transmission-line discontinuities, and multiport subnetworks described by S or Y parameters. These are difficult to analyze using the transient analysis.
- The circuit’s time constants may be large compared to the period of the fundamental excitation frequency. When long time constants exist, it becomes necessary to continue the numerical integration of the equations through many of excitation cycles (i.e. thousands), until the transient part of the response has decayed and only the steady-state part remains. The long integration will consume a large amount of time; furthermore numerical truncation errors in the long integration may become large and reduce the accuracy of the solution. Although algorithms exist to improve this difficulty but it is still complicated.
- Third, each linear or nonlinear reactive element in the circuit adds a differential equation to the set of equations that describes the circuit. A large circuit can have many reactive elements, so the set of equations that must be solved may be very large. For this reason, time-domain analysis is notoriously slow.
